1. Field of the Invention
This invention relates to synchronous belts having teeth spaced along the length thereof and, more particularly, to a method, apparatus and program for estimating noise generated by the belt as it meshes with a cooperating, toothed pulley.
2. Background Art
Noise generation by synchronous belts has long been a problem in the various industries in which these belts are utilized. Many studies have been undertaken in which experiments have been performed to investigate the mechanism by which such noise is generated and to investigate alternative structures through which such noise generation can be reduced. Based on these experiments, it has been found that the source of the most significant noise generation is at the location at which the belt teeth mesh with cooperating pulleys. The noise is produced as a result of impacting of (a) the crests of the belt teeth with a cooperating pulley and (b) the pulley teeth with the bottom land region of the belt.
The following system parameters have been considered in studying noise generation and vibration resulting from the operation of synchronous belts: belt tooth profile; material composition and properties of the belt; pulley tooth profile; speed of the pulley; and applied load. However, the noise/vibration analysis has conventionally been carried out by repeated experimentation. Systems are operated with different synchronous belts for which the above parameters are varied. Noise/vibration evaluation is then conducted. Data is generated based on the changed system parameters. Accordingly, data is generated, and improvements are made, on a trial and error basis. This may involve considerable time and expense.
Aside from the fact that repeated experimentation using different system parameters can be time consuming and costly, the inconsistency of experimental setups has often resulted in inconsistent data production relative to a particular pulley and synchronous belt design. Repeatability of test conditions has been difficult, as a result of which the produced data may not be universally applicable in the industry. Further, it is difficult, and potentially very costly in terms of time and expense, to vary all of the above system parameters through repeated testing to achieve an optimum system construction in terms of noise reduction. As a result of these problems, there does not exist a universal understanding in the industry as to how to analyze noise generation in synchronous belt systems and make changes in system parameters to reduce the generated noise. No effective prior art system for analytically estimating the noise properties of synchronous belt systems is known to the applicant.